All cause and cause specific mortality in obsessive-compulsive disorder: nationwide matched cohort and sibling cohort study

Abstract Objective To estimate the risk of all cause and cause specific mortality in people with obsessive-compulsive disorder (OCD) compared with matched unaffected people from the general population and with their unaffected siblings. Design Population based matched cohort and sibling cohort study. Setting Register linkage in Sweden. Participants Population based cohort including 61 378 people with OCD and 613 780 unaffected people matched (1:10) on sex, birth year, and county of residence; sibling cohort consisting of 34 085 people with OCD and 47 874 unaffected full siblings. Cohorts were followed up for a median time of 8.1 years during the period from 1 January 1973 to 31 December 2020. Main outcome measures All cause and cause specific mortality. Results 4787 people with OCD and 30 619 unaffected people died during the study period (crude mortality rate 8.1 and 5.1 per 1000 person years, respectively). In stratified Cox proportional hazards models adjusted for birth year, sex, county, migrant status (born in Sweden versus abroad), and sociodemographic variables (latest recorded education, civil status, and family income), people with OCD had an increased risk of all cause mortality (hazard ratio 1.82, 95% confidence interval 1.76 to 1.89) and mortality due to natural causes (1.31, 1.27 to 1.37) and unnatural causes (3.30, 3.05 to 3.57). Among the natural causes of death, those due to endocrine, nutritional, and metabolic diseases, mental and behavioural disorders, and diseases of the nervous, circulatory, respiratory, digestive, and genitourinary systems were higher in the OCD cohort. Conversely, the risk of death due to neoplasms was lower in the OCD cohort compared with the unaffected cohort. Among the unnatural causes, suicide showed the highest hazard ratio, followed by accidents. The results were robust to adjustment for psychiatric comorbidities and familial confounding. Conclusions Non-communicable diseases and external causes of death, including suicides and accidents, were major contributors to the risk of mortality in people with OCD. Better surveillance, prevention, and early intervention strategies should be implemented to reduce the risk of fatal outcomes in people with OCD.

a Adjusted for all matching variables (i.e., sex, birth year, county of residence at the time of OCD diagnosis).b Adjusted for all variables in Model 1 and additionally for migrant status (Swedish born v born abroad) and latest recorded highest level of education, family income level, and civil status.c Includes all groups with a small number of deaths (≤10) in the OCD cohort and the causes of death classified in the ICD as 'codes for special purposes'.

puerperium a Certain conditions originating in the perinatal period
Grouped together under 'Other causes of death' given the small number of deaths due to this cause in the study. a

Table B .
Swedish International Classification of Diseases (ICD) codes used to identify lifestime diagnoses of psychiatric disorder comorbidities in the study a Individuals with attention-deficit/hyperactivity disorder (ADHD) were also identified by prescription

Women with OCD (N=35,493) Matched unexposed women (N=354,930) HR (95% CI) Model 1 a HR (95% CI) Model 2 b
Adjusted for all variables in Model 1 and additionally for migrant status (Swedish born v born abroad) and latest recorded highest level of education, family income level, and civil status.c Includes all groups with a small number of deaths (≤10) in the OCD cohort for at least one of the sexes and the causes of death classified in the ICD as 'codes for special purposes'.
a Adjusted for all matching variables (i.e., sex, birth year, county of residence at the time of OCD diagnosis).b

Table D .
Hazard ratios (HRs) with 95% confidence intervals (CIs) for all cause and cause specific mortality among men with obsessive-compulsive disorder (OCD), compared with matched unexposed men Adjusted for all variables in Model 1 and additionally for migrant status (Swedish born v born abroad) and latest recorded highest level of education, family income level, and civil status.c Includes all groups with a small number of deaths (≤10) in the OCD cohort for at least one of the sexes and the causes of death classified in the ICD as 'codes for special purposes'.
a Adjusted for all matching variables (i.e., sex, birth year, county of residence at the time of OCD diagnosis).b

Table E .
Hazard ratios (HRs) with 95% confidence intervals (CIs) for all cause and cause specific mortality among people with obsessive-compulsive disorder (OCD) diagnosed using ICD-10 codes, compared with matched unaffected people Adjusted for all matching variables (i.e., sex, birth year, county of residence at the time of OCD diagnosis).b Adjusted for all variables in Model 1 and additionally for migrant status (Swedish born v born abroad) and latest recorded highest level of education, family income level, and civil status.c Includes all groups with a small number of deaths (≤10) in the OCD cohort and the causes of death classified in the ICD as 'codes for special purposes'. a

Table F .
Hazard ratios (HRs) with 95% confidence intervals (CIs) for all cause and cause specific mortality among people with obsessive-compulsive disorder (OCD), compared with matched unaffected people, excluding people with missing data in the selected covariates